Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum An Experiment - Suggestions request

A while ago, we discussed cleaning the soundboard on another thread : https://www.pianoworld.com/forum/ubb...-%20Cleaning%20the%20ba.html#Post1976350

These are two quotes from the thread:



I have permission to try this on a school piano... A Kimball console that I think dates from the mid-80s (I'll know more later.)

I'll be starting this Friday, in two days.

My plan is this:

This Friday: Measure all the A's with my Verituner. Treat the back with Milseks.

One week later: quickly retreat the back with Milseks. Record any variations in the A's with my VT. Then tune (Rep. Victorian Temperament)

Return in one month: Record any variations in the A's. Re-treat. Re-tune.

Come back after the spring weather moves in: Measure the A's Re-treat. Re-tune.

This piano is difficult to keep in tune. It's in the cafeteria where food is being cooked during the day. Sometimes, they open the windows in the winter. .The building is not air-conditioned in the summer.

The piano is moved all the time.

I believe that I have a record in the piano of general pitch fluctuations from winter to spring and back again... if it is still there.

Anyhow, does anyone here have any suggestions as to another strategy or testing procedure that might work better?

Comments?

This is just a preliminary test to see if treating the board may have merit in some situations. If it does show some promise, then more exacting testing can be done later.

I'll keep this thread updated.

Thanks,
-Joe

Keeping in mind the whole time that piano soundboards have two sides exposed to the environment and that a Kimball from this era may well have a laminated soundboard panel.

ddf

Dont' you need a "control" piano that the only thing you do differently is eliminate the treatment you are testing?

I don't see what you will learn without it?

With the location of this piano, it probably has enough oil on the back of it already. I don't think oil on the soundboard is good for much besides leaving a gummy residue which attracts dust..

Del,
I believe that is does have a laminated board. I'll check to see if the grain is horizontal. Even with the laminated board, the pitch fluctuates wildly.



Ed McMorrow RPT,
You are absolutely correct. A control piano of the same make and model would be ideal. But, I don’t have one. Btw, the Educated Piano was a really valuable book. Some of the best money I ever spent

What I do have is a past record of the behavior of this piano over about a 10 year period. There is a known pattern. What I can see is if using Milseks will alter this pattern... for good or ill.


Jurgen,
I hadn't thought of that. That is a very good point. The back may be covered with grease. I will check. Milseks is an excellent cleaner, though.

Wax finishes will attract dust. The great advantage to using an oil furniture polish is that it doesn't leave a sticky residue behind. Another advantage (although a highly debated one) is that an oil polish can feed the wood. I'm wondering if the oil can penetrate the wood and maybe displace some of the moisture. Maybe this can leave a soundboard that is less sensitive to environmental changes.

Just a a side comment, I described this experiment to a musician that I know. She pointed out that the idea may not be a s outlandish as it first seems... She pointed out that bore oil is used on clarinets and bassoons. She claim that this is to give the instruments greater pitch stability as they are being played..

These are wonderful comments and criticisms.

Thank you and please feel free to keep them coming

I'm all for experimentation.

A company I worked for had a rebuild department that, for a time took the "obvious" solution of coating both sides of the grand soundboards with a finish 1-2mm deep. They used to 'float' the solution onto the soundboard. As outside tuners, we could get an empirical idea of how well it worked. The pianos were all tuned four times a year so there was never much to do to the pianos anyway so under those circumstances there was no discernible difference. Under extreme conditions, the finish crazed. These were showplace pianos in showplace homes and venues so that was undesirable and the project was abandoned. I saw one of these pianos from that era a few days ago. The finish was crazed...it was in a showroom i visited and was losing pitch just like some of the other pianos there.

I have always been surprised at how two or three pianos of the same make, model and age in the same room can react to conditions so differently. Ask any CAUT. I would have to bear this in mind when using a control piano.

Wasn't treating only one side of the soundboard the classic theoretical argument against the DC system?

While you are nott asking for a solution to the presenting problem, since digitalis are encroaching on schools anyway, this would be an ideal location for one. With the cooking ingredients in the atmosphere, electronic engineers might disagree.

I find it embarrassing to be so negative and even more embarrassing to be part of a baying mob on this because, on the face of it, it sounds like such a good idea.

But it is an experiment, ....who knows?, it might just be the resultant build up of dust that helps keep the piano in tune.

Oiling of woodwind instruments is primarily to help prevent the wood from splitting. So there's a point. It also protects the wood from the moisture and other destructive elements in the players breath,
While it will stabilise the instrument somewhat, it is the air inside the instrument that determines the pitch that we hear.

Theoretically, (there's that word again) brass instruments should go flat as they expand with a raise in temperature but in practice they don't. They go sharp because the effect of the air inside the instrument is dominant (in pitch determination) over the instrument itself. Same with all wind instruments.

Hello rxd,

You must be psychic. Several years ago, the district did dispose of a number of pianos and replace them with digitals. I think that they now only keep in use one "real" piano per school I would like to see the next generation of children in the district grow up exposed to real pianos.

The district will not spring for D-C systems.

The pianos are located in the most convenient locations, including the one in the cafeteria. I don 't want to start suggesting that they move the pianos around... I don't want to give the decision makers the impression that even the few pianos that have left are too demanding in their requirements to useful for the district.

I am doing this at my own expense as a thank you for allowing me to try this experiment. Maybe the results will be promising, maybe not. Either way, hopefully at least a little information will be generated that may be of use. If successful, maybe this can lead to myself or others developing some different approach to sounbdboard care in some circumstances. Maybe not I'll report back.

Joe,

Disclaimers: I'm not a professional piano technician and this experience stems from a violin, not a piano.

I have a violin made by the German factory August Clemens Glier in 1919. I took this to Namibia for one year when doing my post-matric there, in 1989. During the extremely dry Namibian winter, some of the hide glue joints split.

I had it repaired, and subsequently started to "feed" the wood, as advised by the violin builder. I think I used furniture oil, and occasionally, almond oil.

Some years later, the violin needed some other repairs, and the subsequent violin builder said that when he wanted to re-assemble it, he had to replace several of the posts / struts, because the old ones had been infiltrated by the oil.

So, while I wouldn't go as far as saying that oil will lead to glue joint failure in itself, I am cautioning that it may lead to glue-up problems if repairs have to be done.

Since, I've stopped "feeding" the wood, but try to use (and replenish) my "Dampit" during the winter.

Mark,

That makes sense. It is something I will particularly in mind when dealing with non-laminated, traditional-type soundboards. I don't think the oil will cause a problem in this case because the board is probably laminated and I think strong, synthetic glues are probably use for the lamination process, as well as for attaching the ribs and bridges.

Your caution is noted

Thank you

You could probably get a good idea of how well oil works as a moisture barrier by trying it on a small piece of wood, changing the humidity, and measuring the changes in dimension, rather than risking causing a problem in a piano. You could do comparative studies of different barriers by using several pieces of wood with different coatings.

Joe:

I think you realize that oiling wood does not seal it completely against moisture. I do believe it will slow down the rate that the moisture content changes. But if the board is finished with lacquer, or whatever, I don't see how the oil would get into the wood.

It is certainly worth a try. Can't think of a better piano to experiment on.

No finish on wood can prevent moisture retention or loss entirely.

From my time in the school system I found that piano in cafeteria locations were subject to excessive humidity exchange more than temp changes.

Not only the preparation of food but the fact that the room fills with people eating food and then empties out several times a day.

As the instrument has no financial value Joe have some fun with experiments.

What you’re going to find out—if, indeed, there are any measurable results at all—is that wood neither wants nor likes to be “fed” with oil although it will probably take some years to find this out. If you have ever encountered a piece of wood that has had oil spilled on it you’ll understand why. The wood ends up punkie, dead and dull.

I smile sadly when I see those advertisements or commercials some bright, young thing—usually in her late teens or early twenties—polishing a room full of exquisite furniture while the blurb goes on about “feeding” or “protecting” the wood. If the finish is still intact, of course, the oil, polish, silicon or wax will never contact the wood at all and no harm is done. So I guess the idea then becomes one of protecting the finish that protects the wood. It doesn’t sound quite as romantic, though, talking about polishing your furniture to “feed” and protect its nitrocellulose lacquer finish.

If the finish film has been broken—i.e., the finish has cracked or checked—and some of the stuff actually does get down to the wood it immediately begins saturating the wood fibers adjacent to the cracks in the finish’s film and goes to work on breaking down the bond between the wood and the finish. Usually this makes the problem worse, not better.

Fortunately the soundboard panel in this piano is probably laminated. The surface veneer is quite thin and it is probably bonded to the core using a resorcinol resin adhesive that is pretty much impervious to any kind of outside chemical attack so any damage to the soundboard panel that results from rubbing it down repeatedly with an oil-based material will be confined to the outer lamination. In terms of the piano’s acoustics it probably won’t be possible to tell the difference.

(Edit: Finishing oils such linseed oil (made from flax seeds) and tung oil (pressed from the nuts of the tung tree) are a somewhat different issue. Both of these oils dry fairly hard when exposed to oxygen. But neither of them, by themselves are a particularly durable wood finish. They are often blended with natural (not waterborne) varnish along with enough turpentine or mineral spirits to make the solution easier to wipe on and off.

These oils and oil/varnish blends will form a somewhat protective film over a wood surface and they will penetrate slightly into the wood’s surface. But neither of them forms a vapor-resistant barrier so it would be unrealistic to expect them to help stabilize the tuning of a piano subjected to a changing environment.)

ddf

Thanks again for all the comments.

I guess that I have 2 ideas:

1) Following the traditional approach-doing nothing- does not seem to protect the soundboard. I see boards locally splitting, ribs delaminating, etc. I think that passively letting nature take its course may not necessarily be the best course of action... at least in some cases.

2) I don't really want to use the oil as a barrier. I want to see if the oil can displace some of the wood's own moisture content with something a little more stable. If we can raise the wood's content of natural oils, maybe it will change dimensions less with variations in humidity. For instance, I "think" that woods with a naturally high oil content, like rosewood, are more dimensionally stable.

Jeff, you really don't seem at all impressed by those old Kimballs

Well, I can certainly understand the desire to do something that might help. But understanding the causes of all that splitting, rib delaminating, etc. is the best way to start. The reasons for this deterioration are fairly well known nowadays and quite a bit has been written on this subject in the Piano Technician's Journal.

The best solution, of course, is to first build the piano in a way that does not encourage this kind of deterioration. And then in doing what is possible to stabilize the localized environment around the soundboard. Dampp-Chase systems, properly installed and maintained, really do work. So far, other than building more stable pianos in the first place, this has proven to be the most successful approach.





I think I understand what you have in mind. Knowing what I know about wood finishes, however, I'm skeptical about your basic premise.

And I'm not alone; the following is quoted from an article written by Bob Flexner, a professional furniture maker and author of several books and numerous articles on wood finishing:

"Myth: Furniture polish replaces natural oils in the wood.

"Fact: Common furniture woods [spruce is among these -- ddf] never contained natural oils, and no wood “needs” oil. Even the few exotics, such as teak and rosewood, that do contain natural oil don’t need it replenished—especially not with the petroleum-based solvents contained in furniture polishes."

Still, I await the results of your experiment with interest....

ddf

Thanks, Del

This is an old beater piano that has severe pitch stabilization problems because of its highly variable environment. A D-C system is out of the question. But, a way needs to be found to stabilize the pitch.

I'll just attempt this and report back on what I find. If things improve, then maybe this can be at least some sort of clue as to a better approach to soundboard care. If it fails, that's OK, too. Then, we know not to go any further down this particular road. The way I see it, either way, everyone wins. Even the district wins. They get some free care for their piano. So the money allocated for this, this year, can go elsewhere.

A while back, I emailed the folks at Milseks re using their product on the piano soundboard. The following is their response, published here with their permission:

And for another perspective go to:
http://www.thefinishingstore.com/bob-flexners-feature-article-march/

ddf

Hi Del,

I just read the article. It seems very convincing.

The problem is, there are other convincing views on the net as well.

It seems to me that if the finish really seals the wood that effectively, then it should not be reacting to changes in humidity. But, we know that a soundboard does react to changes in humidity. Thus, there must be some degree of permeability in the finish.

After Googling a bit more, I am beginning to wonder if pure Milseks would be the best route, or maybe Milseks with some other component, like maybe olive oil, almond oil, or grapeseed oil, using the Milseks as a carrier, might be the better approach.

I have until tomorrow (today) at 4 PM to decide.

Thank you for your perspective. It is respected and appreciated

Edit: I wonder if bore oil might also be a possibility.

Edit: I think I am going to stick with just pure Milseks. It was the original concept. If there is any indication of improved pitch stabilization, then other refinements can be tried later.